1. Field of the Invention
The present invention is generally in the field of electronic circuits and systems. More specifically, the present invention is in the field of amplifier circuits and systems.
2. Background Art
Switching power amplifiers, including Class-D amplifiers, provide efficient amplification, which may be particularly important for applications in which a battery is used as a power supply. Switching power amplifiers may also improve the efficiency or reduce the power of mobile communication devices, such as audio headsets and cellular telephones. Despite being potentially desirable, conventional switching audio amplifiers can pose serious shortcomings when implemented in mobile communication devices.
One shortcoming is that the analog driver of a conventional switching power amplifier is prone to power supply noise. Particularly in a mobile communication device such as a cellular telephone, in which the battery also powers radio frequency transmitters, power supply noise may seriously degrade the signal quality and undermine the potential benefits provided by use of a switching power amplifier. Another shortcoming is that a conventional switching power amplifier is not easily scalable with advancements in process technology. Moreover, a conventional switching power amplifier that supplies a high pulse rate signal consumes large amounts of dynamic power and can have its performance severely degraded by switching errors.
Accordingly, there is a need to overcome the drawbacks and deficiencies in the art by providing a switching amplifier architecture that is scalable with advances in process technology, displays enhanced supply rejection, and is suitable for implementation as an audio amplifier in a mobile communication device.